PSX is a PHP framework for creating RESTful APIs. It helps you to build clean URLs serving Web standard formats like JSON, XML, Atom, and RSS. It includes a handler system that abstracts away SQL queries from domain logic, a routing system that executes correct controller method for the location of the controller and the method annotation, and a flexible data system that converts database records into formats like JSON, XML, Atom, and RSS. A lightweight DI container handles dependencies. The controller supports request and response filters that can modify the HTTP request or response, and filters are provided for Basic and Oauth authentication.